head to head
Neither is meaningfully harder - they pose close to the same test. The widest gap is execution, and it is a single point.

Optimization · Pure Optimization
A faction-driven RPG-shooter where build and route planning shape every ending.

Optimization · Practiced Mastery
A loot-heavy open-world action RPG with flashy combo combat and a famously breakable crafting system.
Fallout: New Vegas leans Optimization (Pure Optimization); Kingdoms of Amalur: Reckoning leans Optimization (Practiced Mastery).
Kingdoms of Amalur: Reckoning leans a little harder on execution, though the gap is small.
Fallout: New Vegas
Shooter inputs with VATS assist
Kingdoms of Amalur: Reckoning
Dodge-and-combo combat, forgiving timing
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Fallout: New Vegas
Scripted factions and enemies
Kingdoms of Amalur: Reckoning
Enemies never adapt to your habits
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Fallout: New Vegas
Some loot and crit RNG
Kingdoms of Amalur: Reckoning
Loot rolls add light randomness
Fallout: New Vegas leans a little harder on optimization, though the gap is small.
Fallout: New Vegas
Faction routing, perks, builds heavily rewarded
Kingdoms of Amalur: Reckoning
Destiny builds and crafting trivialise difficulty
A matching score does not mean a matching test. Two games can both sit at 10 on execution and demand completely different things of you - which is why the reasoning above matters more than the number beside it.